76 XL1000 Sporty

We have a 1976 XL1000 that I love to ride. Due to the customization done to it Bob cannot ride it anymore because it kills his back but I love it and would like to get it out of moth balls. 4 years ago we had a S&S carb on it with 2 inch drag pipes and it ran fine except 3 different times the carb caught on fire. Bob took it to a local guy and put a new S&S carb on it. From then on it ran like crap. Started fine, Idled fine but as soon as you went thru the gears it broke up until you got to cruising speed. We have 3 others that we ride so he just put it in the garage. So now I want to get it on the road again. Does anyone have any suggestions?

Carb rejetting?
Points problem? Could a change over to Electronic do the trick?

He took it back to the same guy (he was reputable) before we parked it and the guy said he needed to change the pipes. It worked before on a S&S carb and Bob flat out won't change the pipes. Thanks for the help!!!!!